Data from uncontrolled studies of patients with failed spinal fusion suggests that noninvasive electrical stimulation results in a significantly higher fusion rate. The lack of controlled clinical trials is balanced by the fact that these patients served as their own control. The most common bone stimulators include low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field therapy. Data from a randomized controlled clinical trial of patients meeting the criteria for high risk for development of failed fusion suggests that invasive or noninvasive electrical bone stimulation as an adjunct to spinal fusion surgery is associated with a significantly higher spinal fusion success rate in the treated group compared with the control group.
The Food and Drug Administration, in 1994, approved the use of LIPUS for use in accelerating fresh fracture healing, and in 2000, for treatment of established nonunions. Similarly, electrical stimulation has been approved for the treatment of nonunions in the United States. Basic science research supports the use of LIPUS in signal transduction, gene expression, blood flow, and tissue modeling and remodeling. Multiple, small randomized trials have also supported the use of LIPUS.
This modality may also be useful in patients at high risk of nonunion. These include: Fusion to be performed at more than one level
Current smoking habit
Diabetes or other metabolic diseases where bone growth is poor
Documented history of alcoholism
Obese patients who are at greater than 50% over their ideal body weight
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